cell histogram

Plugins/LindtLeerformPlugin/Views/CalibrationWindow.axaml.cs

@@ -1,13 +1,22 @@
 using Avalonia.Controls;
+using Avalonia.Input;
+using Avalonia.Media.Imaging;
 using LindtLeerformPlugin.ViewModels;
 
 namespace LindtLeerformPlugin.Views;
 
 public partial class CalibrationWindow : Window
 {
+    private static readonly Cursor HandCursor = new(StandardCursorType.Hand);
+    private static readonly Cursor DefaultCursor = new(StandardCursorType.Arrow);
+
     public CalibrationWindow()
     {
         InitializeComponent();
+
+        PreviewImageControl.PointerMoved += OnPreviewPointerMoved;
+        PreviewImageControl.PointerPressed += OnPreviewPointerPressed;
+        PreviewImageControl.PointerExited += OnPreviewPointerExited;
     }
 
     protected override void OnClosing(WindowClosingEventArgs e)
@@ -15,4 +24,64 @@ public partial class CalibrationWindow : Window
         (DataContext as CalibrationWindowViewModel)?.Dispose();
         base.OnClosing(e);
     }
+
+    private (int x, int y)? ToImageCoordinates(Avalonia.Point pointerPos)
+    {
+        if (PreviewImageControl.Source is not Bitmap bitmap)
+            return null;
+
+        var ctrlSize = PreviewImageControl.Bounds.Size;
+        var imgSize = bitmap.Size;
+        if (ctrlSize.Width <= 0 || ctrlSize.Height <= 0 || imgSize.Width <= 0 || imgSize.Height <= 0)
+            return null;
+
+        var scale = System.Math.Min(ctrlSize.Width / imgSize.Width, ctrlSize.Height / imgSize.Height);
+        var displayW = imgSize.Width * scale;
+        var displayH = imgSize.Height * scale;
+        var offsetX = (ctrlSize.Width - displayW) / 2;
+        var offsetY = (ctrlSize.Height - displayH) / 2;
+
+        var imgX = (pointerPos.X - offsetX) / scale;
+        var imgY = (pointerPos.Y - offsetY) / scale;
+
+        if (imgX < 0 || imgY < 0 || imgX >= imgSize.Width || imgY >= imgSize.Height)
+            return null;
+
+        return ((int)imgX, (int)imgY);
+    }
+
+    private void OnPreviewPointerMoved(object? sender, PointerEventArgs e)
+    {
+        if (DataContext is not CalibrationWindowViewModel vm)
+            return;
+
+        var coords = ToImageCoordinates(e.GetPosition(PreviewImageControl));
+        if (coords == null)
+        {
+            PreviewImageControl.Cursor = DefaultCursor;
+            return;
+        }
+
+        var cellIndex = vm.HitTestCell(coords.Value.x, coords.Value.y);
+        PreviewImageControl.Cursor = cellIndex.HasValue ? HandCursor : DefaultCursor;
+    }
+
+    private void OnPreviewPointerExited(object? sender, PointerEventArgs e)
+    {
+        PreviewImageControl.Cursor = DefaultCursor;
+    }
+
+    private async void OnPreviewPointerPressed(object? sender, PointerPressedEventArgs e)
+    {
+        if (DataContext is not CalibrationWindowViewModel vm)
+            return;
+        if (!e.GetCurrentPoint(PreviewImageControl).Properties.IsLeftButtonPressed)
+            return;
+
+        var coords = ToImageCoordinates(e.GetPosition(PreviewImageControl));
+        if (coords == null)
+            return;
+
+        await vm.ShowCellHistogramAsync(coords.Value.x, coords.Value.y, this);
+    }
 }